1. Field of the Invention
This invention concerns a device for hydraulic command of thrust reversal for jet engines.
2. Description of the Prior Art
In jet or gas turbine aviation engines, there are known methods making it possible to reverse the propulsive thrust of the engine. These methods may be, principally in the case of cold flow use, of a classical type in which an engine commands at the same time both the rotation of deflecting flaps or barriers and the axial slide of panels covering the reversal grid. The reversing units are activated by jacks which are moved, through flexible shafts and geared transmissions, by a rotary hydraulic engine which is part of a hydraulic command device, itself fed by the aircraft's high pressure circuit.
There are two areas of uncertainty during the research phase of designing a thrust reverser: prior to flight testing, little is known about the real stresses to which the thrust reverser will be subject in operation, and little is known about how such stresses change over time. The difficulties stemming from these areas of uncertainty are compounded by the problems resulting from flow limits imposed by the hydraulic feed circuit of the aircraft, while the device's required response time is very short, on the order of 1.5 second. Accordingly, optimal use must be made of whatever maximum flow is available.